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Go to Editorial ManagerIn this research, experimental and analytical deep drawing of the several-stages design mold is produce hexagonal cup and also proved the influence of the thickness of the sheet on the allocation of strain and laminating in curvature of the cup area for all stages of the drawing. Three stages deep drawing mold was designed and constructed to carry out the experimental work required to produce a hexagonal cup of (28.25 mm by 24.5 mm) , (60 mm) high drawn from a circular flat sheet (80 mm diameter), made from low carbon steel (1006–AISI). Analysis program (ANSYS11.0) to perform the finite element method to accomplish the analytical side of the search. Three types of thickness sheet (tt°= 0.5, 0.7,1 mm) with constant radius of curvature of punch equal to (RRpp =4) mm, radius of curvature of die equal to (RRdd=8 mm)and radius of curvature of wall of die (RRcc= 4 mm) were used. From the experimental and analytical results of the three stages of drawing, it has been found that drawing load less than the more advanced stages of drawing operation on the wall of cup, maximum laminating take place at curvature of the cup area with sheet thickness equal to (tt°=0.5 mm) and maximum thickeningtake place at the at throat cup with sheet thickness equal to (tt°=1 mm), the maximum values of strains (radial, hoop, thickness andeffective)take place at throat cup with sheet thickness equal to (tt°=1 mm).
Kids carrying heavy loads as a part of everyday activity may be related to bend their trunks forward to maintain body posture and balance while walking. This study was to determine a correlation between the weight of a child's backpack, their body weight, and certain features of their body posture. The study group consisted of 6 children, in age of primary school. The anthropometry (age, length, weight) were taken for each volunteers. A school backpack was specially built for the present study. Walking gait was filmed in three cases: (zero kg, 3 kg and 6 kg) backpack.Posture was analyzed by using (Kenova and MATLAB) computer programs.The results show that the forward inclination of the trunk increases when the load and the walking distance are increased, this forward inclination segment may impose greater stress over the vertebral column (ligaments and intervertebral disks) and increase the risk of back problems.Spine and back health may be adversely affected by load carriage and it may be important to use spinal curvature as a measure of posture for load carriage. This study shows that the backpack load cause a lumbar asymmetry by 10 to 20 degree according to the load which has a significant amount of back pain in kids.
In this paper an experimental works conducted to study the behavior of R.C. beam with large web opening at different locations and fortified with reactive powder composite (RPC) at the extreme tension zone (bottom edge of opening) and/or extreme compression zone (Top edge of opening). The experimental study is investigate the behavior of twelve beams and study the ability of using normal strength concrete together with RPC in the same section to exploit the advantages of these two materials in optimal way. The main variables are RPC layers locations in tension zone and/or in compression zone and the locations of openings. The ultimate loads, load mid-span deflection behavior and strain for steel and concrete were discussed. The experimental results showed that the ultimate strength was decreased with increasing number of opening about 4% for beams with two openings located in shear zone and 21% for beams with three openings, thus indicating that the stiffness decreases accordingly. The using RPC layers effectively enhanced performance of hybrid beams when compared with using the normal strength concrete layers only. The using RPC layers in compression and tension zones increased the ultimate load about 47 % for beams with two opening located in shear zone, when using RPC in the tension zone and normal strength concrete in the compression zone the ultimate flexural load and ultimate deflection increase little compared with normal concrete.